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Foot-and-mouth disease (FMD) is one of the most infectious viral transboundary diseases of livestock, which causes devastating global economic losses. Different enzyme-linked immunosorbent assays (ELISAs) are used for sero-surveillance of the foot-and-mouth disease virus (FMDV). However, more sensitive, accurate, and convenient ELISAs are still required to detect antibodies against FMDV serotypes. The primary goal of this study was to establish serotype-specific monoclonal antibody (mAb)-based blocking ELISAs (mAb-bELISAs) that would provide better performance characteristics or be equivalent in performance characteristics compared with a conventional polyclonal antibody (pAb)-based competitive ELISA (pAb-cELISA). Four mAb-bELISAs were developed using FMDV serotype-specific mAbs for the detection of anti-FMDV/O/A/Asia1/SAT2 antibodies. Using a 50% cut-off, all four mAb-bELISAs exhibited species-independent 99.74%, 98.01%, 96.59%, and 98.55% diagnostic specificity (DSp) and 98.93%, 98.25%, 100%, and 87.50% diagnostic sensitivity (DSe) for FMDV serotypes O, A, Asia1, and SAT2, respectively. In addition, a 100% DSe of serotypes O- and SAT2-specific mAb-bELISAs was observed for porcine sera when the cut-off was 30%. All mAb-bELISAs developed in this study displayed high repeatability/reproducibility without cross-reactivity. Finally, the diagnostic performance of mAb-bELISAs was found to be better than or equivalent to compared with pAb-cELISAs, suggesting that mAb-bELISAs can be used to replace existing pAb-ELISAs for the detection of antibodies against these four FMDV serotypes. [ABSTRACT FROM AUTHOR]

Owner-, farmer-, or herdsman-reported disease prevalence is widely used in veterinary epidemiologic studies (1-6), especially for diseases that produce visible external lesions (e.g., ovine myiasis, foot-and-mouth disease [FMD]) (1,5) or [...]

There are conflicting data regarding whether activation of γ-aminobutyric acid-B (GABA-B) receptors results in inhibition of tumor growth and invasion. The objectives of this study were to document the effects of the GABA-B receptor agonist baclofen on malignant hepatocyte proliferation and migration. We also sought to determine whether any effects on cell migration were mediated by changes in cyclic adenosine monophosphate (cAMP) signaling or matrix metalloproteinase (MMP) expression. Finally, GABA-[B.sub.1] and -[B.sub.2] receptor expression was documented in 2 malignant hepatocyte cell lines (PLC/PRF/5 a h-7) and 12 sets of human hepatocellular carcinoma and adjacent nontumor tissues. Cell proliferative activity was documented by WST-1 absorbance, migration by wound healing assays, cAMP levels by enzyme-linked immunoassay (ELISA), MMP by immunohistochemistry and ELISA, and GABA-B receptor expression by flow cytometry and reverse transcriptase--polymerase chain reaction. Although baclofen had no effect on cell proliferation, wound healing was delayed, an effect that was reversed by the GABA-B receptor antagonist CGP. cAMP levels were decreased in Huh-7 but not PLC cells exposed to baclofen. MMP expression remained unaltered in both cell lines. Finally, GABA-[B.sub.1] receptor expression was present and consistently expressed, but GABA-[B.sub.2] expressi on was limited and varied with the number of cell passages and (or) duration of culture. In conclusion, activation of GABA-B receptors has no effect on malignant hepatocyte proliferation but does decrease cell migration. This inhibitory effect may involve cAMP signaling but not MMP expression. GABA-[B.sub.2] receptor expression is limited and variable, which may help to explain discrepancies with previously published results. Key words: hepatocellular carcinoma, metastases, GABA, baclofen, neurotransmitters, proliferation, migration. Il existe des donnees contradictoires quant a savoir si l'activation des recepteurs de l'acide g-aminobutyrique B (GABA-B) provoque l'inhibition de la croissance des tumeurs et de leur invasion. La presente etude a eu comme objectif, d'une part, de documenter les effets de l'agoniste des recepteurs GABA-B, baclofene, sur la proliferation et la migration des hepatocytes malins; d'autre part, de determiner si les effets sur la migration cellulaire sont vehicules par des modifications dans la signalisation de l'adenosine monophosphate cyclique (AMPc) ou dans l'expression de la metalloproteinase matricielle (MMP); finalement, d'examiner l'expression des recepteurs GABA-[B.sub.1] et GABA-[B.sub.2] dans deux lignees cellulaires d'hepatocytes malins (PLC/PRF/5 et Huh-7) et 12 ensembles de carcinomes hepatocellulaires humains et tissus sains adjacents. On a examine l'activite proliferative des cellules par l'absorbance de WST-1, la migration par des essais de cicatrisation, les taux d'AMPc par la methode ELISA, la MMP par immunohistochimie et ELISA, et l'expression des recepteurs GABA-B par cytometrie de flux et RT-PCR. Bien que le baclofene n'ait pas eu d'effet sur la proliferation des cellules, la cicatrisation a ete retardee, un effet qui a ete renverse par l'antagoniste des recepteurs GABA-B, CGP. Les taux d'AMPc ont diminue dans les cellules Huh-7 mais pas dans les cellules PLC exposees au baclofene. L'expression de la MMP est demeuree inchangee dans les deux lignees de cellules. En fin, l'expression des recepteurs GABA-[B.sub.1] a ete constante, mais celle des recepteurs GABA-[B.sub.2] a ete limitee et a varie avec le nombre de passages cellulaires et (ou) la duree de la culture. Ainsi, l'activation des recepteurs GABA-B n'a pas d'effet sur la proliferation des hepatocytes malins, mais elle ne diminue pas la migration des cellules. Cet effet inhibiteur pourrait impliquer la signalisation de l'AMPc, mais pas l'expression de la MMP. L'expression des recepteurs GABA-[B.sub.2] est limitee et variable, ce qui pourrait expliquer les divergences entre ces resultats et ceux publies anterieurement. Mots-cles : carcinome hepatocellulaire, metastases, GABA, baclofene, neurotransmetteurs, proliferation, migration., Introduction Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third most common cause of cancer death in the world today (El-Serag and Rudolph 2007). Although most prevalent [...]

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